Johannesburg -LRB- CNN -RRB- -- Operators of a South African gold mine negotiated with about 15,000 striking workers Monday after they walked off the job the night before , a company official said .

`` At this stage , the reason for the strike remains unclear , but we hope to gain clarity as soon as possible , '' said a statement from Peter Turner , a Gold Field executive vice president . `` The situation in the mine has been calm and peaceful since the start of the strike , and we appeal to all stakeholders to continue to act with restraint and to engage in good faith .

`` It is important that we restore normality in a peaceful manner and as soon as possible , '' he said .

Management called the strike at the KDC Gold Mine on the West Rand `` Unlawful and unprotected . ''

The striking miners could not immediately be reached for comment .

The KDC workers join about 28,000 other miners who are already on strike at the Lonmin PLC platinum mine in Marikana , about two hours northwest of Johannesburg .

August 16 clashes at the Lonmin mine left 34 people dead and 78 wounded , sparking national outrage .

Management at Lonmin set a Monday deadline for strikers to return to work , but workers did not appear to heed the call , as several thousand were marching outside the facility .

The violence in August erupted after negotiations between striking workers and Lonmin broke down and police decided to fence in the machete-armed miners with barbed wire , police said . Thousands of mineworkers had been striking for days for higher wages .

Lonmin has so far missed out on around $ 75 million in lost production , and the workers have n't been paid for a month .

The company said last week that a `` peace accord '' had been signed , but key unions had not agreed to the deal .

Late last month , a regional prosecutor charged 270 of the platinum miners with the murder of their colleagues , who are believed to have been shot by police .

However , a national prosecutor has said that authorities would dismiss the provisional charges and release the miners , pending further investigation .

South Africa drops murder charges against miners

Last week , 47 of the miners appeared in court and were ordered released .

Lawyers for the miners had called the decision to charge them with murder `` bizarre in the extreme . '' The country 's justice minister called the charges shocking and confusing .

Clashes also erupted last week between protesters and security officers outside Gold One 's Modder East gold mine in Springs , about 24 miles -LRB- 39 kilometers -RRB- east of Johannesburg , police said . The violence occurred after former employees staged a protest outside the mine 's gates , Johannesburg police Capt. Pinky Tsinyane said .

The protesters had been fired for participating in an earlier illegal strike , the company said .

CNN 's Aja Harris contributed to this report .

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The striking miners join 28,000 others who walked off the job at another mine

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Violence at Lonmin 's Marikana platinum mine left 44 people dead last month

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The company set a Monday deadline for returning to work